Human embryonic stem cells (hESCs) cells are pluripotent cells that can differentiate into a large array of cell types. Stem cells are distinguished from other cell types by two important characteristics. First, they are unspecialized cells capable of renewing themselves through cell division, sometimes after long periods of inactivity. Second, under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions. In some organs, such as the gut and bone marrow, stem cells regularly divide to repair and replace worn out or damaged tissues. In other organs, however, such as the pancreas and the heart, stem cells only divide under special conditions.
Stem cells have potential in many different areas of health and medical research. Some of the most serious medical conditions, such as cancer and birth defects, are due to problems that occur when cells undergo a transformation. Understanding normal cell development and differentiation mechanisms will allow for a better understanding of these conditions.
Another potential application of stem cells, is making cells and tissues for medical therapies. Today, donated organs and tissues are often used to replace those that are diseased or destroyed. Unfortunately, the number of people needing a transplant far exceeds the number of organs available for transplantation. Stem cells offer the possibility of a renewable source of replacement cells and tissues to treat a myriad of diseases, conditions, and disabilities including Parkinson's disease, amyotrophic lateral sclerosis, spinal cord injury, burns, heart disease, diabetes, and arthritis.
Generation of retinal pigmented epithelial cells (RPEs) from human pluripotent stem cells (hpSCs) is a vital component of cell-based strategies for treatment of degenerative eye diseases. Before hpSC-derived RPEs can be administered in therapeutic modalities, however, chemically defined culture conditions must be developed that reproducibly and robustly induce vascular differentiation. RPEs represent a unique option for the treatment of dry AMD and wet AMD. The methods disclosed herein provide for the generation of a homogenous population of RPEs from hPSCs that can be used for cell therapies of eye disease or drug discovery.